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M Howaldt

Publications and source records attributed to M Howaldt.

4 recordsLinked to original sources
PubMed1996

Model-based monitoring and control of a monoclonal antibody production process.

A structured mathematical model describing the dynamics of hybridoma growth and monoclonal antibody (mAb) production in suspension cultures is presented. The model fits well to experimental data obtained from batch, fed-batch, and continuous cultures with hybridoma cells. Applications of the model for process control are demonstrated. 1. An extended Kalman filter (EKF) was designed to estimate the state of the process. The oxygen consumption rate of the cell culture is monitored on-line and is used as the only measurement information for the EKF. This EKF is able to provide good estimates for living and dead cell densities and the medium composition. 2. The mathematical model can be applied for the optimization of fed-batch cultures.

Amino Acids, Essential↗
PubMed1994

Automated imunoanalysis systems for monitoring mammalian cell cultivation processes.

Two different automated immunoanalysis systems are presented. Both are based on the principles of flow-injection analysis and were developed to provide reliable, rapid monitoring of relevant proteins in animal cell cultivation processes. One system uses a turbidimetric analysis, and the other employs a heterogeneous chemistry with immobilized immunocomponents. For both systems, the analysis time is in the range of a few minutes, and a complete analysis cycle, including triplicate analyses and various washing steps, is in the range of 20-30 minutes. Samples from cultivation processes can be analyzed directly without dilution. Quantitation of proteins such as rt-PA or monoclonal antibodies can be performed over an analyte concentration range of 1-1000 mg/L. Both systems were compared to conventional ELISA assays on microtiter plates. The turbidimetric analysis system also included a biosensor for simultaneous glucose determination.

Animals↗
PubMed1993

On-line immunoanalysis for bioprocess control.

Immunoanalytical techniques such as ELISA are often used for the detection of proteins produced in cultivation processes. Owing to the difficulty of automating of the time-consuming traditional ELISA, there is an intense demand for a suitable on-line monitoring method. Combining well-known immunoassays with the FIA technique, we present the heterogeneous and the turbidimetric immuno-FIA methods. The following proteins were investigated with these FIA methods: thermostable pullulanase, IgG, antithrombin III, and recombinant tissue-type plasminogen activator. In the cases of pullulanase and monoclonal mouse IgG, the turbidimetric immuno-FIA was used for on-line analysis of the cultivation process. Results are presented here to demonstrate the effectiveness and application of these immunoanalysis.

Antithrombin III↗